Soldato
If your eldest is "crusty" and there are no signs of spots on your youngest, then I would risk taking the holiday. You wouldn't take your youngest child out of school "just in case" they are infectious, nor would I not go on holiday.
IF spots start to appear before you leave, then I would abandon the holiday.
Agreed. In fact the school would probably get quite annoyed if you kept them away just in case.
Grandparents will be with us so we’ll probably just keep the little one entertained away from the more crowded areas like the pool if he takes a turn for the worse.